Renewable cartridge fuse



T. A. BOTH.

RENEWABLE CARTRIDGE FUSE. APPLICATION HLED ULY18, 1913.

'Patented May 30,1922.

l A\\\\\\\\\\\\\\\\\\\\\\v 7 4/ l ATTORNEY UNITED STATES PATENT omer..y

TONJES A. BOTH, OF STRATFORD, CONNECTICUT, ASSIGNOR TO THE CONNECTICUTELECTRIC MANUFACTURING COMPANY, A CORPORATION OFCONNECTICUT.

RENEWABLE CARTRIDGE FUSE.

Application filed July 18,

neetieut, have invented an Lmprovement in Renewable Cartridge Fuses, ofwhich the following is `a specication.

This invention relates .to renewable cartridge fuses of both the erruleand :blade .types and vhas 'for its object toprovide a fuse ventilatedat the ends and `provided with ree Jractory heads so as to preventinjury to a marble switch `base in the event of the blow out, to prevent-arcing, to prevent iusing oi? any of the movable yparts and to preventthe substitution ot wire. for a i'use strip inthe event of a blow out. Afurther object of the invention is to providea fuse strip having stopsso located withrelationto the heads as to properly locate theindications on the strip with relation to the holes in the ferrules.

With these and other objects in view, I have devised .the renewableiiuse which I will now describe referring to the accompanying drawingforming a part-oi this specification and using reference characters toindicate the several parts.

Figure l is a side elevation of one `of .my novel fuses ot the .terruletype;

Figure 2 `an end elevation corresponding therewith Figure 3 a sectiononthe .lineB-B in Figure il;`

Figure l a longitudinal section of a fuse oii the ferrule type;

Figure 5 a perspective view oi' one of the refractory heads, detached;

yFigure 6 a perspective view of the fuse strip, detached; l

Figure 7 a perspective view of one end of a fuse ot' the iferrule type,showing the parts disassembled;

Figure S a side elevation et one endo-f a 4fuse of the blade type;

Figure Sa a longitudinal section o'ii the other end of the luse, whichhas been given a quarter turn; y j 1 Figure 9 an end elevation partlybroken away,as seen from the rightin Figure Sn;

Specification of Letters Patent.

Patented May 30, 1922.

1918. Serial No. 245,550.

Figure l0 a similar view illustrating a variant 'form of blade, and

Figure ll is a section on the line 11.-11 in Figure l0.

2O denotes the body which is ordinarily a iibre tube, and is externallythreaded at its ends for vengagen/lent by internal threads on theerrules 2l. The ends of the body are closed by heads which are made ofrciractory or relatively non-fusible material, being preferably mouldedtrom vitreous material, as" porcelain or glass. can be used itpreferred, or even a high grade oi compressed fibre. I preferably,however, use vitreous material as it cannot be drilled an Adconsequently prevents the substitutionofwire ior a 'fuse strip in theevent ot a blow out.` 23 denotes the y'luse strip which is preferablymade narrowest at its midlength so that fusing will taire place midwaybetween `the heads, and is provided "with indications 24 which show thesafetyT1 ainperage ofi theflusefand with stops 25, 4which are shown asformed by displacing metal of the strip laterally, vand are so locatedwith relation to the headsas to prevent longitudinal movementand iiX theindications', when assembled, in alinement with holes 26 in the Bakeliteierrules, which in this 'form may beplaced centrally. The heads areprovided with slots 27, ordinarily vplaced at one side ofthe center,.with shoulders Q8 adapted to .resten `the ends et" the body, with 'lugs29 adapted =to engage notches 30 in the ends of the' body yto lool; theheads and body against relative 'rotary movement, and in their edgeswith one or more .*entilating channels which permit the gases generatedby a blow outto pass through without danger of burstingthe bodyorblowing oft' fthe head. A

ln assembling, one end of the ijuse strip `is .passed through the slotina head, the corresponding stop is drawn against the inner side oi? the'head andthe end of the fuse strip is bent over the outer side oit Athehead, asin Figure .7, leaving the indication visible. The head `is theninserted in the `body with the lugs on the head in engagement with thenotches in the body, and the lerrule is turned to place. `hen the otherend ot the Ytuse passed through the slot in the other he: l, thc stop isdrawn against the inner side o1'E the head and the head is seated in theend ol the body as bei'ore, except that the head is given a halt turn soas to place the slot on the opposite side oi? the body which causes theiuse strip to pass obliquely through the body. rIhen the end ot theiiuse strip is bent over the outer side ot the head as before and thelerrule is turned to place. It will be noted that the thickness ol thefuse strip, which is clamped between the head and the terrule, at eachend, leaves the head and the ferrule separated and provides a gaschamber, indicated by 32; From this chamber, in the event olf a blowout, the gas can pass out freely through holes in the end of theferrule,

In devising my present construction care has been taken to avoid seriousobjections to fuses now upon the market. The effective end ventilationprevents injury to a marble base and prevents either bursting oi. thebody or blowing off of a head in the event oit a blow out, and thenon-use oit metallic parts with the exception of the ierrules, which areei?- iectively insulated by the body and the heads, does away with alldanger or arcing, and with all danger of the fusing of metallicconnecting parts which has heretobeiore rendered many so calledrenewable fuses useless after a blow out.

It is of course well understood that the smaller sizes of fuses, that isfuses it'or G0 amperes and under, are ordinarily oit the ferrule typeand fuses for 100 amperes and upward are of the blade type. In Figures 8to ll inclusive I have illustrated forms ot renewable fuses of the bladetype, the ditference being that in the latter type the circuit isthrough the blades which are in electrical contact with the fuse strip.

In Figures 8a and 9, 34e denotes the blade which is formed from a pieceoi? sheet metal tubing flattened to place the sides in parallelism butnot in contact. The object being to leave a longitudinal passage betweenthe sides of the flattened tube 'for the escape ot gas through the bladeitself Yfrom chamber 82 in the event of a blow out. The inner end of theblade is provided with a base 3G which is formed by splitting theflattened tube and bending the sides outward at right angles to theblade. The base is provided at one side ofthe blade with a hole 37through which the indication is visible. In this form the heads areprovided on the outer side at the edges with notches 38 which areengaged by lugs 39 on the bases. These lugs and notches lock the bladesagainst rotary movement relatively to the heads and insure that theholes 37 will always be in alinement with the indications, The`lierrules in this torni, .indicated by a0, are provided with relativelylarge holes 4:1 through. which the blades eX- tend and the indicationsare visible.

The form illustrated in Figures 10 and ll diifers in that the blade,indicated by 42, is formed from a flat bar or strip of metal which issplit at its inner end and the base i3 is formed by bending the sidesoutward at right angles to the blade as before. The ventilation in thisform is through holes 44 in the base. 'Ihe notches 38 and lugs 39 arethe same as in the other form.

Having thus described my invention, I claim:

l. In a fuse of the character described an insulating tubular body,removable refractory heads closing the ends of the body and providedwith slots and in their edges with ventilating channels, a iuse strippassing through the slots and having its ends bent over the outer sidesoit the heads, and ferrules having holes in their ends and threadedengagement with the body.

2. In a iuse ol thc character described an insulating tubular bodyhaving notches in ils ends, removable refractory heads having shouldersengaging the ends of the body, and provided. with slots, lugs engagingthe notches, a. fuse strip passing through the slots and having' itsends bent over the outer sides of the heads, and ferrules engaging thebody.

3. In a fuse oi the character described a body, removable refractoryheads closing the ends of the body and provided in their ed withVentilating channels, a fuse strip passing through the heads and havingits ends bent over the outer sides oit the heads, ferrules engaging thebody and leaving chainbcrs between the heads and the terrules, and meansfor permitting escape oit gas trom, the chambers.

4. In a :fuse an insulating tubular body, refractory heads havingVentilating channels, a fuse strip passing through the heads,ventilating blades having bases contacting with the iuse, and Ferrulesengaging the body.

5. In a fuse an insulating tubular body, refractory heads havingVentilating channels, a fuse strip passing through the heads,ventilating blades comprising fiat metal tubes having the side walls attheir ,inner ends bent outwardly in opposite directions, and ferrulesengaging the body by which the parts are retained in place.

6. In a fuse an insulating body, a fuse strip, blades having aVentilating passage extending longitudinally therethrough. and means torconnecting the blades to the body.

7. A Ventilating fuse blade comprising a fiat metal tube with the sidesof the inner end of the tube bent outwardly in opposite directions toformv a base.

S. A blade for a cartridge fuse having a Ventilating passage extendinglongitudinally therethrough. l u a 9. A head for renewable cartridgefuses made of refractory material and provided with a fuse slot, andwith one or more ventilating channels in its edge.

`10.` A head for renewable cartridge fuses made of refractory materialand provided with Shoulders, with a lug, with'a fuse slot7 and with oneor more ventilatingchannels in its edge.

In testimony whereof I aiiix my signature.

TONJES A. BOTH.

